the short answer is yes, a handful of times.
when i was in high school a neighbor broke into my car
and stole my calculator ...
in high school i was a news paper carrier, and i saved
and saved and eventually had enough for a nice racing bike ( bike not moto )
i upgraded the freewheel and everything else ... and in college a few years later
someone stole it ...

a friend lifted one of those vacuum pump things with the rubber cork from my studio.
someone grabbed my college ring.

when we moved from boston to providence, the moving company didn't have a interstate license
(they lied)
and they stole a box of our stuff they saw us packing at the last minute.
inside was a dremel, 5 or 6 nice photography books, all our flatware,
and a hand made folio of 60 or 70 contact prints ( 4x5 ) i made of a city block that was
being torn down in cambridge, ma. it was like a habs project,
but i did it no-fee .. i made 3 hand made folios of the prints and donated
one set to the library and one set to historical commission
and kept one set for me ...
the project consisted of building and people portraits
--- exterior views, interior views, birds eye views, and portraits of people who worked in the city block &C ...
everything probably dumped everything but the dremel,
and since they didn't have an interstate license we had no recourse.

soon after we moved into our apartment, the kid the landlord hired to
do yard work, odds 'n ends &C for him tried to jimmy the door of our place
open and grab what he could.
my wife came home and was climbing up the stairs and scared him off.
she heard his footsteps in the attic, saw all the wood shavings and doorframe
on the ground and when she looked out the window, she saw the landlord driving off with the kid ...

knock wood - its been almost 10 years, and nothing stolen in a while. lots of misplaced stuff, but nothing stolen.

In 30+ years as a photographer and 20 of it self employed I have never had insurance at all. I own a sh*tload of stuff but the only thing ever taken from my car was a analog Pentax spot meter in 1985 that I replaced with a digital one that still works.

I did have a check book stolen from my studio that cost my bank 2000 dollars.

The worst camera gear thefts I've endured were A: a Walker Titan 4x5 (the triple-extension model), B: my Olympus E-1 digital camera and my MacBook laptop, iPod and some other odds and ends (they ignored the $5K worth of Hasselblad gear sitting out), and C: a knife I used as a prop for a number of my Tarot Card series shots that I bought from a custom knife-maker at the Maryland Renaissance Festival, along with several 8x10 trophy aluminum wet-plate images I made. The subject of the plates was the thief. Other than that, the worst theft was a car (my absolutely beloved 1991 red Volkswagen GTI 16v).